The present invention relates to the type of spring coiling machine wherein wire is fed intermittently from a source of supply along a longitudinal path and is coiled during the feeding operation by a coiling tool or abutment to form springs, cut-off occurring at the end of each wire feeding and coiling operation. While not necessarily so limited, the invention is particularly applicable to spring coiling machines of the general type shown in:
U.S. Pat. No. 2,199,002 issued May 31, 1938 to Bergevin and Nigro.
U.S. Pat. No. 2,455,863 issued Dec. 7, 1948 to E. W. Halvorsen.
U.S. Pat. No. 2,820,505 issued Jan. 21, 1958 to E. E. Franks et al.
U.S. Pat. No. RE-24,345 issued Aug. 20, 1957 to C. R. Bergevin.
U.S. Pat. No. 2,902,079 issued Sept. 1, 1959 to Costello et al.
U.S. Pat. No. 2,923,343 issued Feb. 2, 1960 to Franks.
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U.S. Pat. No. 3,009,505 issued Nov. 21, 1961 to Franks.
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U.S. Pat. No. 3,402,584 issued Sept. 24, 1968 to Cavagnero.
U.S. Pat. No. 3,934,445 issued Jan. 27, 1976 to Lampietti.
More particularly, the invention relates to improved drive means for spring coiling machines of the general type mentioned. Prior art spring coiling machines fall into two general categories, the "segment type" and the "clutch type". Segment type coilers are noted for a high degree of accuracy and repeatability in spring coiling operations but such machines are found somewhat lacking in flexibility. That is, during set up operations, the use of change gears is necessary when it is desired to change spring configuration and wire feed length over a wide range. Further, it will be obvious that feed length cannot be changed "on the run". Still further, severe limitations are encountered in a relative amount or degree of cyclic time available for feeding, coiling and cut-off operations.
In the case of "clutch type" spring coiling machines some improvement in machine flexibility and versatility is achieved. That is, severe limitations on the ability to change the length of wire feed are overcome and set-up operations are somewhat less onerous. Such machines, however, are not wholly satisfactory. Their accuracy and repeatability are found somewhat lacking and in the present state of the art they are inferior in this respect to "segment type" spring coiling machines.
The present invention incorporates the best features of both "segment type" and "clutch type" spring coiling machines.